Table 1.

The characteristics of literature with inclusion and exclusion criteria

Researcher	Year	Country	Cancer/normal	Methods	Sample
TCGA	2016	USA	485/44	qPCR	Tissue
Bhavna K. et al [14]	2012	USA	15/15	qPCR	Tissue
Manikanda. et al [21]	2015	India	52/8	qPCR	Tissue
Li W. et al [22]	2014	China	8/8	qPCR	Tissue